PSU does not always power up all GPUs

[fugasjunior]

Hi.
I'm having a problem with my 6 GPU ethereum mining rig.

One 750W PSU feeds the motherboard, SSD and 3 GPUs with risers. This one works perfectly well. The other 650W PSU linked to three GPUs and their risers causes problems. After powering on the computer, a random number of these 3 GPUs does not turn on, and thus doesn't show in Windows at all. This happens randomly, sometimes all of them turn on successfully, sometimes none of them, most of the times just 1 or 2.

I have tried four different PSUs - 650W and 750W Corsair Gold, everything works perfectly well with these. However, either of 650W and 750W EVGA Bronze PSUs causes these issues. All of these PSUs work properly on other rigs, I've tested it. It's weird because a 750W EVGA Bronze feeds the motherboard and has no issues, and when I try to hook second one to the rest of the GPUs, this issue keeps happening.

Full specs:
Intel Celeron G3930
6x RX 470 8GB (modded bios, overclocked, however this issue persists even with all original settings)
4 GB RAM (virtual memory set to 18GB)
120 GB SSD
Gigabyte GA-H110-D3A motherboard (yup, all BIOS settings configured properly, spent a lot of time checking that)
EVGA Bronze 750W (powering 3 GPUs, 3 risers, MB and SSD, works perfectly well)
EVGA Bronze 650W (with either this one or the 750W one, the issue arises)
PSUs are linked with a dual PSU starter.

Any ideas what to do? I'd prefer to keep the EVGA 650W in the rig. Thanks in advance!

[leonix007]

Hi.
I'm having a problem with my 6 GPU ethereum mining rig.

One 750W PSU feeds the motherboard, SSD and 3 GPUs with risers. This one works perfectly well. The other 650W PSU linked to three GPUs and their risers causes problems. After powering on the computer, a random number of these 3 GPUs does not turn on, and thus doesn't show in Windows at all. This happens randomly, sometimes all of them turn on successfully, sometimes none of them, most of the times just 1 or 2.

I have tried four different PSUs - 650W and 750W Corsair Gold, everything works perfectly well with these. However, either of 650W and 750W EVGA Bronze PSUs causes these issues. All of these PSUs work properly on other rigs, I've tested it. It's weird because a 750W EVGA Bronze feeds the motherboard and has no issues, and when I try to hook second one to the rest of the GPUs, this issue keeps happening.

Full specs:
Intel Celeron G3930
6x RX 470 8GB (modded bios, overclocked, however this issue persists even with all original settings)
4 GB RAM (virtual memory set to 18GB)
120 GB SSD
Gigabyte GA-H110-D3A motherboard (yup, all BIOS settings configured properly, spent a lot of time checking that)
EVGA Bronze 750W (powering 3 GPUs, 3 risers, MB and SSD, works perfectly well)
EVGA Bronze 650W (with either this one or the 750W one, the issue arises)
PSUs are linked with a dual PSU starter.

Any ideas what to do? I'd prefer to keep the EVGA 650W in the rig. Thanks in advance!

what I see is that there is a delay on powering the other 3 with extra PSU, are you using ADD2PSU?

just to isolate or to prove if my assumptions are correct, you may use the paper clip technique the idea is to power on first the extra PSU with 3 GPU's then Turn on your system.

[fugasjunior]

what I see is that there is a delay on powering the other 3 with extra PSU, are you using ADD2PSU?

just to isolate or to prove if my assumptions are correct, you may use the paper clip technique the idea is to power on first the extra PSU with 3 GPU's then Turn on your system.

Yes, I'm using ADD2PSU. I've just tested the paper clip technique, seems to solve the issue, however it's not exactly what I'd like to keep it at. I've also found that when all risers were powered from the same PSU that powers the motherboard, this also solved the issue but brought another one - when I turned the PC off via Windows, the CPU fan keeps running for some reason.

[xberg]

Hi,

Same problem here.

I heard that's it's a very bad idea to use a different PSU for risers than for the GPU: ie you SHOULD have a PSU power both the riser and the GPU: never use 2 GPU for a single riser-GPU combo.

Anyways to your problem: same thing exactly here. I'm also use ADD2PSU. The problem occurs with many different PSU:
- Corsair 850W Gold
- Seasonic Prime Gold 750W
- EVGA GQ 650W Gold

Happens on 3 rigs.

Unlike you I use for all my rigs 3 or 4 PSU: never only 2.

I tried changing the ADD2PSU when this problem occcurs. This did not help.

Unlike you this affects ALL cards for a PSU: ie I never have just 1 card from 1 PSU turn on and not the other ones.

After spending countless hours I just gave up: I now have a system that detects how many GPUs are running in my system and it's below the normal number the system reboots. Until the correct amount is found.

[ivakar]

Maybe you should go for different setup? like one psu will power your mb, cpu, ssd, all risers, while other psu will power all gpu cards? actually all of my rigs are working by this sheme and I've never had problems as you described

[fugasjunior]

I've tried almost all possible combinations, using different ADD2PSU, different risers, PSUs, everything. Only the EVGA PSUs cause this issue. In the end I gave up and decided to just go for the paperclip method, it was not worth so much trouble.